The utility model discloses a coal gasification fine ash carbon extraction device. The device comprises a gasification clarification tank which is connected with a gasification system through a supernatant pipeline, wherein the bottom of the gasification clarification tank is connected with the flotation unit through the slurry stirring and reverse flocculation pretreatment unit, an overflow pipeline at the upper part of the flotation unit is connected with the pulverized coal thickening tank through the defoaming device, and a lower-layer bottom material outlet at the bottom of the pulverizedcoal thickening tank is connected with the pulverized coal bin through a solid-phase outlet of the pulverized coal diaphragm filter pressing device; the device has the advantages of being simple in structure, reasonable in design, high in resource utilization rate, environmentally friendly, stable and efficient in device operation and obvious in economic benefit, and related agents can be recycled.